Fossil Coral (Rugose)
Rugosa (Order), often preserved in Limestone (CaCO3)
sedimentary
Category
Sedimentary (Secondary Classification For A Weathered Mineral Specimen)
Browse sedimentary (secondary classification for a weathered mineral specimen) specimens identified by the Rock Identifier community.
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Quartz (Druzy)
Silicon Dioxide (SiO2)
mineral
Chert (Jasper-bearing)
Microcrystalline silica (SiO2) with iron oxide inclusions
sedimentary
Quartz (Druzy or Geode fragment)
Silicon Dioxide (SiO2)
mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O
mineral
Turquoise
Hydrated phosphate of copper and aluminum; CuAl6(PO4)4(OH)8·4H2O
mineral
Flint
Chert (a form of cryptocrystalline quartz, chemical formula SiO₂)
Mineral
Limestone with Calcite Veins
Calcium Carbonate (CaCO3)
sedimentary
Quartz (Milky/Clear)
Silicon Dioxide (SiO2)
mineral
Sandstone (with Iron Staining)
Clastic sedimentary rock (SiO2 with Fe2O3 impurities)
sedimentary
Gold Flakes in Oil (Novelty Specimen)
Native Gold (Au)
mineral
Quartzite Cobble
Quartzite (primarily SiO2)
metamorphic
Sandstone (River Rock)
Arenite (SiO2 principal component)
sedimentary
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement (primarily SiO2 with Fe2O3/FeOOH)
sedimentary
Chert (with Iron Staining)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (likely Quartzose)
Arenite
sedimentary
Basalt
Basalt (Mafic volcanic rock)
igneous
Hematite
Iron(III) oxide (Fe2O3)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Picture Jasper
Silicified sedimentary or volcanic rock (primarily SiO2)
sedimentary
Quartz (Grain)
Silicon Dioxide (SiO2)
mineral
Jasper
Jasper (Silica-rich Microcrystalline Quartz, SiO2)
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Quartz / Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Basalt Pebble
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Granite Pebble (Pink Granite)
Phaneritic Igneous Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
igneous
Sandstone Beach Pebble
Clastic sedimentary rock (SiO2 with iron oxide cement)
sedimentary
Quartz
Quartz (SiO2, Silicon Dioxide)
Mineral
Limonite Pseudomorph after Pyrite
Limonite (FeO(OH)·nH2O) replacing Pyrite (FeS2)
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Specular Hematite
Hematite (Iron(III) oxide, Fe2O3)
mineral
Pebble (likely a type of sandstone or quartzite pebble)
Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.
Sedimentary rock
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
mineral
Chert Pebble
Microcrystalline Quartz (SiO2)
sedimentary
Epidote Water-Worn Pebble
Epidote {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
metamorphic
Black Limestone with Calcite Veining
Limestone (CaCO3) with Calcite (CaCO3) inclusions
sedimentary
Moqui Marble (Ironstone Concretion)
Goethite/Hematite Concretion (Fe2O3 / FeO(OH))
sedimentary
Chert (specifically Flint)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
sedimentary
Vesicular Basalt (or Scoria)
Vesicular Basalt
igneous
Basalt with inclusion
Basalt (Aphanitic-Porphyritic texture)
igneous
Chalcedony (Common Agate)
Silicon Dioxide (SiO₂)
mineral